Prior attempts to provide a disposable respiratory nose filter generally fall within one of two categories: mask-style nose filters, i.e., those which are designed to cover the exterior of the nostrils of the nose; and, intrusive-style nose filters, i.e., those which are designed to be inserted into a nasal passageway of the nose.
U.S. Pat. No. 5,392,773 and the patents listed therein generally disclose mask-like nose filters. Specifically, U.S. Pat. No. 5,392,773 discloses a mask-like filter which includes a meshed filter region surrounded by an adhesive region. The adhesive region further includes tabs which adhere to the base, lateral and tip portions of the nose.
U.S. Pat. Nos. 3,774,601 and 4,984,302 disclose the use of cotton, wool, polyethylene or polyester as a material used to filter particulate in a nose filter attached to the exterior of the nose. Both filters, however, cover a large portion of the facial area and can irritate the skin it comes is contact with. Generally speaking, mask-like nose filters are extremely awkward, cumbersome and unsightly. Further, when mask-like nose filters become wet, they cling or stick to the face of the wearer making it difficult to speak or breathe. Additionally, such nose filters lack aesthetic appeal.
Intrusive-style nose filters are disclosed in U.S. Pat. Nos. 3,457,917, 3,905,335, 4,052,983 and 5,417,205. U.S. Pat. No. 3,457,917 discloses a non-disposable nose filter which includes a filter retaining means (i.e., a housing), filtering material, and a detachable cap having a finger gripping means provided at the end of the cap. Unlike the present invention, the filter retaining means in U.S. Pat. No. 3,457,917 is formed from a hard molded plastic such as polytetrafluorethylene or Bakelite.
U.S. Pat. No. 3,905,335 discloses a nasal air filter comprising a pair of interconnected cylinders having a filter material contained within. The cylinders further contain yieldable flange means which engage the inner nostril walls.
U.S. Pat. No. 4,052,983 discloses a filter device insertable into the nasal passages which include a pair of flexible casings, each casing releasable receives a filter cartridge. The filter cartridges have a multitude of cilia-like, nylon filaments which act to electrostatically charge the air as it moves past the filaments, thus aiding in the filtering process.
U.S. Pat. No. 5,417,205 discloses an air filter comprised of two filter units linked by a connecting element. Each filter unit further comprises first and second gauze filters and a plurality of rods which extend from the first gauze filter to the second gauze filter and retain a stack of wet filter cloth between the gauze filters.